Auto-focus system

ABSTRACT

The present invention provides an auto-focus system comprises: an auto-focus device for controlling a focus of a taking lens by making an object in a range of an AF area in an imaging range of a camera an auto-focus object and automatically focusing on the object in the range of the AF area; a size/shape adjustment operating member used for changing both the size and the shape of the AF area; a selection device for selecting a subject from the size and the shape of the AF area by operating the size/shape adjustment operating member; and an AF area changing device for changing the subject selected by the selection device based on the operation to the size/shape adjustment operating member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an auto-focus system, more specificallyto an auto-focus system that can change the position, the size, theshape or the like of an AF area, which is an object range of anauto-focusing (AF) in an imaging range of a camera.

2. Description of the Related Art

In an imaging system for converting an image of the object intoelectronic signals (image signals) by a shooting element (CCD) such as atelevision camera, usually a contrast scheme is adapted as an auto-focus(AF) scheme. The contrast scheme is a scheme for automatically focusingin the best focus condition (focus condition) by detecting a contrast inan object image from image signals of the object image captured by animaging device and controlling a focus of a taking lens (focus lens) sothat it has the highest contrast.

An AF, which is one of the contrast schemes, makes only an object in apart of an imaging range as the object instead of making the entireimaging range of a camera the object range of AF. For example, imagesignals in a predetermined range, which is an object of AF, is extractedfrom image signals of the object image effectively imaged by an imagingelement, and based on the image signals in the extracted range, focus iscontrolled so that the image has the highest contrast. In this manner,an object of AF is limited to an object in a part of the range. In thisspecification, an object range of AF is called “AF area” and a frameindicating a range of the AF area (the outline of the AF area) is called“AF frame”.

If a single AF area is fixed to a predetermined position in an imagingrange, usually a rectangular AF area is set in the center of the imagingrange, however, a technique for enabling an AF area to be changed to adesired position in response to an operator's operation is known (forexample, see Japanese Patent Application Laid-Open No. 2003-224759). Asa conventional method for indicating the position of an AF area, amethod for moving the AF area to an objected position by moving the AFarea vertically and horizontally to an imaging range, for example, isknown.

It is effective to enable the size or the shape of an AF area to bechanged in addition to the position of the AF area, as the size or theshape of the AF area can be adjusted to match the size or the shapewithin an imaging range for the object to be focused on. The otheroperating members are needed, however, to enable the size or the shapein addition to the position of the AF area to be changed. Particularly,in order to enable the size or the shape of an AF area to be changed inmultiple-steps (continuously), an operating member, such as a turningdial, for enabling an operating position to be changed among multiplecontinuous positions and a position sensor (volume or the like) fordetecting the operating position by volume level or the like arerequired instead of a simple two-step switch. If sets of the operatingmember and the position sensor are provided separately for adjusting thesize of an AF area and for adjusting the shape of an AF area, spaces forrespective purposes are needed. This causes a problem in that anappliance to be provided with such an operating member and a positionsensor (a lens body, a controller or the like) is difficult to bedownsized.

Even if a position of an AF area is enabled to be changed, the size orthe shape (aspect ratio) of the AF area is not appropriate for somesizes or shapes in a range for an object, on which a cameraman or thelike wants to focus, or some surrounding situations of an object. Thiscauses a problem in that an object to be focused on sometimes cannot befocused on.

SUMMARY OF THE INVENTION

The present invention is adapted in view of the circumstances, andintends to provide an auto-focus system, which enables a space for anoperating member for operating an AF area to be smaller. The presentinvention also intends to provide an auto-focus system, which enables arange of an AF area to be set so that an intended object is focused onby AF.

In order to achieve the above object, an auto-focus system of a firstaspect comprises: an auto-focus device for controlling a focus of ataking lens by making an object in a range of an AF area in an imagingrange of a camera an auto-focus object and automatically focusing on theobject in the range of the AF area; a size/shape adjustment operatingmember used for changing both the size and the shape of the AF area; aselection device for selecting a subject from the size and the shape ofthe AF area by operating the size/shape adjustment operating member; andan AF area changing device for changing the subject selected by theselection device based on the operation to the size/shape adjustmentoperating member.

According to the present invention, a single operating member isselected to be used as an operating member for changing either the sizeor the shape of an AF area by a selection device such as a switch sothat a single size/shape adjustment operating member can be used foradjusting both the size and the shape of an AF area without needingoperating members for adjusting the respective purposes to be providedseparately. This reduces a space which should have been needed forplacing operating members for adjusting the size and the shape of an AFarea to a space for placing a member and downsizes an AF area operatingunit for placing the operating member.

The size and the shape of an AF area are not always required to beadjusted when a picture is taken. With a priority subject (which isfrequently changed) being selected by the selection device to be changedby a size/shape adjustment operating member, a problem seldom occurs inthat the subjects cannot be changed concurrently.

An auto-focus system according to a second aspect is the inventionaccording to the first aspect, wherein the size/shape adjustmentoperating member can be set to continuous operating positions and the AFarea changing device transfers the subject selected by the selectiondevice in a continuous state when an operating position of thesize/shape adjustment operating member is continuously changed. In orderto enable the size and the shape of an AF area to be continuouslychanged, the size/shape adjustment operating member must set tocontinuous operating positions as in the present invention. In thiscase, a space for placing such operating members needs to be large ifsuch operating members are provided separately for adjusting the sizeand for adjusting the shape of an AF area. Therefore, it is effective touse a single size/shape adjustment operating member for adjusting boththe size and the shape.

An auto-focus system of a third aspect is the invention according to thefirst or the second aspect, further comprising a position adjustmentoperating member for changing a position of the AF area, wherein the AFarea changing device changes a position of the AF area based onoperation to the position changing operating member. The presentinvention is an aspect which is provided with an operating member forchanging a position of an AF area separately.

An auto-focus system of a forth aspect is the invention according to thefirst, second, or third aspect, wherein the size/shape adjustmentoperating member is provided on a controller with an operating memberfor operating a focus or a zoom of the camera or on a driving unit seton the side of a lens barrel of a taking lens. That is to say, if an AFarea operating unit placed with the size/shape adjustment operatingmember is placed on a controller for a focus or a zoom or on a drivingunit, the controller or the driving unit can be smaller.

An auto-focus system of a fifth aspect comprises: an auto-focus devicefor controlling a focus of a taking lens by making an object in a rangeof an AF area in an imaging range of a camera an auto-focus object andautomatically focusing on the object in the range of the AF area; anaspect ratio inputting device for indicating and inputting an aspectratio of the AF area; and an aspect ratio changing device for changingan aspect ratio of the AF area to the aspect ratio inputted by theaspect ratio inputting device. According to the present invention, as anAF area can be changed to have a desired aspect ratio, an appropriaterange can be set as an AF area based on the shape of the object to befocused on. This improves reliability of focusing on the desired object.

An auto-focus system of a sixth aspect is the invention according to thefifth aspect, wherein the aspect ratio changing device changes an aspectratio of the AF area while keeping the area of the AF area to a certainvalue by changing the vertical length and the horizontal length of theAF area. According to the present invention, the vertical length and thehorizontal length are changed with the area of the AF area being kept asit is. If the size of the AF area, which can be defined by an area ofthe AF area, is appropriate, any change to the aspect ratio of the AFarea does not cause a problem in that the size of the AF area isinappropriate. Changing such as exchanging the vertical length and thehorizontal length of the AF area can be easily performed.

An auto-focus system of a seventh aspect is the invention according tothe fifth aspect, wherein the aspect ratio changing device changes anaspect ratio of the AF area by changing either the vertical length orthe horizontal length of the AF area. Unlike the invention according tothe second aspect, the invention can change an aspect ratio of an AFarea also by changing either the vertical length or the horizontallength of the AF area without keeping the area of the AF area to acertain value as in the invention of the third aspect.

An auto-focus system of a eight aspect is the invention according to thefifth aspect, wherein the aspect ratio inputting device comprises: afirst inputting device for indicating and inputting an aspect ratio ofthe AF area when only the vertical length is changed while thehorizontal length of the AF area being kept to a certain value; and asecond inputting device for indicating and inputting an aspect ratio ofthe AF area when only the horizontal length is changed while thevertical length of the AF area being kept to a certain value; andwherein the aspect ratio changing device changes the vertical length ofthe AF area to the aspect ratio indicated and inputted by the firstinputting device and changes the horizontal length of the AF area to theaspect ratio indicated and inputted by the second inputting device. Inthe present invention, an aspect ratio can be changed by changing eitherthe vertical length or the horizontal length of the AF area and the size(area) of the AF area can be adjusted by adjusting the vertical lengthand the horizontal length.

An auto-focus system of a ninth aspect is the invention according to anyone of the aspects from the fifth aspect to the eighth aspect, whereinthe aspect ratio changing device changes an aspect ratio of the AF areawithout changing the center position of the AF area. According to thepresent invention, as the center position of the AF area does not changeeven if an aspect ratio of the AF area is changed, the problem in that aposition of the AF area is inappropriate does not occur even if anaspect ratio of the AF area is changed when the position of the AF areais appropriate.

An auto-focus system of a tenth aspect is the invention according to anyone of the aspects from the fifth aspect to the ninth aspect, whereinthe aspect ratio changing device changes an aspect ratio of the AF areawithout changing the center position of the AF area, if an entire rangeof the AF area is contained in the imaging range of the camera, andchanges an aspect ratio of the AF area by changing the center positionof the AF area so that the entire range of the AF area is contained inthe imaging range of the camera, if the entire range of the AF area isnot contained in the imaging range of the camera. According to thepresent invention, a part of an AF area may stick out from the edge ofthe imaging range when an aspect ratio of the AF area is changed withoutchanging the center position of the AF area. As an aspect of an actiontaken for the case, the present invention is an aspect for changing thecenter position of the AF area so that the entire AF area is containedin the imaging range.

An auto-focus system of a eleventh aspect is the invention according toany one of the aspects from the fifth aspect to the tenth aspect,further comprising: a size inputting device for indicating and inputtingthe size of the AF area; and a size changing device for changing thesize of the AF area to the size inputted by the size inputting devicewhile keeping the aspect ratio of the AF area as it is. The presentinvention is for enabling a cameraman or the like to change the aspectratio of an AF area and the size, i.e., the area of the AF area.

An auto-focus system of a twelfth aspect is the invention according toany one of the aspects from the fifth aspect to the eleventh aspect,further comprising: a position inputting device for indicating andinputting a position of the AF area; and a position changing device forchanging a position of the AF area to the position inputted by theposition inputting device. The present invention is for enabling acameraman or the like to change an aspect ratio of an AF area and aposition of the AF area.

An auto-focus system according to the present invention enables a spacefor placing operating members for operating an AF area to be smaller. Acameraman or the like can correctly set a range of an AF area to focuson an object, on which the cameraman or the like wants to focus, so thatan object intended by the cameraman or the like can be focused on theobject. This broadens the range of AF applications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an outline view showing an embodiment of a television camerasystem applying the present invention;

FIG. 2 is a block diagram showing a configuration of an auto-focussystem;

FIG. 3 is a diagram exemplifying a range of an AF area in an imagingrange;

FIG. 4 is a plane view showing a front of a focus demand with an AF areaoperating unit shown from a viewpoint of a standing cameraman;

FIG. 5 is a schematic diagram showing a case where a position of an AFarea is moved vertically and horizontally in the imaging range;

FIG. 6 is schematic diagram showing a case where the size of an AF areabecomes bigger/smaller in the imaging range;

FIG. 7 is a schematic diagram showing a case where the shape of an AFarea is changed in the imaging range;

FIG. 8 is an outline view of a driving unit of an ENG lens provided withan AF area operating unit;

FIG. 9 is a block diagram showing a configuration of another embodimentof an auto-focus system according to the present invention;

FIG. 10 is a diagram exemplifying a range of an AF area in an imagingrange;

FIG. 11 is a plane view showing an outline of an AF area operating unit;

FIG. 12 is a schematic diagram used for explanation of changing theposition of the AF area;

FIG. 13 is a schematic diagram used for explanation of changing the size(area) of the AF area;

FIG. 14 is a schematic diagram used for explanation of changing theshape (aspect ratio) of the AF area;

FIG. 15 is a schematic diagram used for explanation of changing theshape (aspect ratio) of the AF area; and

FIG. 16 is a schematic diagram used for explanation of a certainsituation in changing the shape (aspect ratio) of the AF area.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of an auto-focus system according to the presentinvention will be described with reference to the attached diagrams.

FIG. 1 is an outline view showing an embodiment of a television camerasystem applying the present invention. As shown in FIG. 1, a televisioncamera 10 includes a lens unit 12 and a camera body 14 and is supportedon a camera platform 18 set on a pedestal dolly 16.

Two operation rods for left and right 22 and 24 are extending from thecamera platform 18, with a focus demand (focus controller) 26 being setby a mounting clamp 38 on a grip part 22A of the right operation rod 22and a zoom demand (zoom controller) 28 being set on a grip part of theleft operation rod 24. The focus demand 26 and the zoom demand 28 areconnected with a predetermined connector on the lens unit 12 via cables.

Focus knobs 30 that can be tuned are provided on the focus demand 26.When the focus knobs 30 are turned, a focus control signal, whichindicates to move a focus (focus lens) to a target position of the focusposition according to the turned position, is provided from the focusdemand 26 to the lens unit 12. In response to the signal, the focus lensof the lens unit 12 moves to the target position indicated by the focuscontrol signal.

As detailed later, the focus demand 26 has an integrated AF areaoperating unit including operating members such as an AF start switchfor indicating to start auto-focus (AF), and joy sticks for operatingthe position, the size and the shape of an AF area, which is an objectrange of AF.

The zoom demand 28 has a thumb ring 34 that can be tuned. When the thumbring 34 is turned around the zoom demand 28, a zoom control signal,which indicates to move a zoom (zoom lens) in a target speed of the zoomspeed according to the turned position, is provided from the zoom demand28 to the lens unit 12. In response to the signal, the zoom lens of thelens unit 12 moves in the target speed indicated by the zoom controlsignal.

On the camera body 14, a viewfinder 36, which is a display device, isprovided. As the viewfinder 36 displays an image of an object taken bythe camera 10, the cameraman can shoot the object with a desiredcomposition by operating the focus demand 26 and the zoom demand 28 asviewing the image. A range of an AF area, which is an object range ofauto-focus (AF), can be shown by an AF frame, which indicates an outlineof the range, and the AF frame is displayed as superimposed on the imageof an object on a screen of the viewfinder 36. Therefore, when AF isperformed, the cameraman can recognize which range the object can befocused on in a shooting range (imaging range) and adjust the AF area toa desired range by operating the AF area operating unit placed on thefocus demand 26.

FIG. 2 is a block diagram showing a configuration of an auto-focussystem applied to the abovementioned television camera system. Theauto-focus system shown in FIG. 2 includes the lens unit 12, a camerabody 14, a viewfinder 36, and an AF area operating unit 54 integrated inthe focus demand 26.

The lens unit 12 includes a CPU 50 and AF processing unit 52. The lensunit 12 has an optical system (taking lens) (not shown) for imaging anobject light on an imaging surface of the imaging element of the camerabody 14. The optical system has a group of lenses, which is movable inthe direction of an optical axis of a focus lens, a zoom lens or thelike and a group of fixed lenses. The group of movable lenses is drivenby motor (not shown) according to control signals from the CPU 50. TheCPU 50 controls the position or the speed of the focus lens or the zoomlens.

The focus lens is controlled (focus control) by manual focus (MF) orauto focus (AF). When it is controlled by MF, focus control signalsoutputted from the focus demand 26 shown in FIG. 1 in response tooperation of the focus knobs 30 are obtained by the CPU 50 and the focuslens is controlled to move to the target position indicated by the focuscontrol signals.

When it is controlled by AF, focus information (focus evaluation value)detected by the AF processing unit 52 is provided for the CPU 50 and thefocus lens is controlled according to the focus information. Imagesignals of the image taken by the imaging element are generated in thecamera body 14 and the image signals (brightness signals) are providedfrom the camera body 14 to the AF processing unit 52. The AF processingunit 52 detects a contrast in the object image based on the imagesignals.

Assuming that an object or a range of an object image, which iseffectively imaged by the imaging element of the camera body 12, iscalled “imaging range”, an AF area 92, which is an object range of AF,is set in a rectangular range of an AF frame 94 for the imaging range90, for example, as shown in FIG. 3. The position, the size and theshape in the AF area 92 (AF frame 94) in the imaging range 90 arechanged according to AF area information provided from the AF areaoperating unit 54 as described later. The imaging range 90 shown in FIG.3 corresponds to an imaging range of the television camera 10 as well asto a screen range of an object image taken by the imaging element of thecamera body 14 (image) when the image is displayed on a screen of theviewfinder 36 or the like.

In FIG. 2, image signals provided from the camera body 14 to the AFprocessing unit 52 include image information on the entire of theabovementioned imaging range. The AF processing unit 52 extracts onlythe image signals in the range of the AF area from the image signals andadds up high frequency components of the image signals for each field(for each screen). This sequentially gives values indicating contrastsof an object image in an AF area. The value (added up value) is called“focus evaluation value” in this specification.

The CPU 50 sequentially obtains the focus evaluation values as focusinformation from the AF processing unit 52 and moves the focus lens tothe position where the focus evaluation value is the biggest (maximum).This enables an object in the AF area is automatically focused on.

Image signals obtained by the imaging element of the camera body 14 areprovided from the camera body 14 for the viewfinder 36, whose screen isadapted to display the currently taken image. The CPU 50 of the lensunit 12 is adapted to provide AF area information (information on theposition, the size and the shape of the AF area) for the camera body 14,indicating a range of the abovementioned AF area, which is currently setas an object range of AF. Signals of the AF frame (an outline of the AFarea) indicating the range of the current AF area is combined with theabovementioned image signals to be outputted to the viewfinder 36, basedon the AF area information in the camera body 14, and an image of an AFframe 94 indicating a range of the current AF area 92 is displayed onthe screen of the viewfinder 36 with the image of the imaging range 90,as shown in FIG. 3. With this display, the cameraman can recognize therange of the current AF area.

The AF area operating unit 54 is an operating unit for setting andchanging the position, the size and the shape of an AF area, andintegrated in the focus demand 26. FIG. 4 is a plane view showing anappearance of the focus demand 26. As shown in FIG. 4, the focus demand26 includes a body unit 80 on a cylinder with integrated variouscircuits. The body unit 80 has the abovementioned focus knob 30 that canbe turned for indicating a target position to move a focus lens in theMF mode. On the circumference of the body unit 80, an AF start switch isplaced and a joy stick 62, an AF frame size/shape adjustment dial 64 andan AF frame adjustment selection switch 66 are arranged as operatingmembers of the AF area operating unit 54.

The AF start switch 82 is a switch for starting AF. When the AF startswitch 82 is turned on in the MF mode, the signal is provided for theCPU 50 of the lens unit 12 and the AF process is started in the CPU 50.AF is switched to MF in response to turning of the focus knob 30.

The joy stick 62, which is placed as an operating member of the AFoperating unit 54, is a directional member for adjusting a position ofthe AF area (AF frame). When the joy stick 62 is tilted up or down or tothe left or to the right, the position of the AF frame moves up or downor to the left or to the right on the screen (on the imaging range) asdescribed later.

The AF frame size/shape adjustment dial 64 is an operating member usedfor adjusting both the size and the shape of the AF area (AF frame).When the AF frame size/shape adjustment dial 64 is turned, the size orthe shape of the AF area is changed, while the center of the AF area isfixed as described later.

The AF frame adjustment selection switch 66 is a two-step slide switchfor selecting either to use the AF frame size/shape adjustment dial 64as an operating member for adjusting the size of an AF area (AF frame)or to use it as an operating member for adjusting the shape of the AFframe. When the AF frame adjustment selection switch 66 is set to thedown side in FIG. 4, the size of the AF area can be adjusted in responseto the operation of the AF frame size/shape adjustment dial 64. When theAF frame adjustment selection switch 66 is set to the up side in FIG. 4,the shape of the AF area can be adjusted.

A CPU for performing each type of process in response to operation ofeach operating member is mounted on the body unit 80 of the focus demand26. The CPU performs process in response to operation of the focus knob30 or operation of the AF start switch 82, as well as process as the AFarea operating unit 54. In FIG. 2, the CPU of the focus demand 26 isshown as the CPU 60 of the AF area operating unit 54.

In FIG. 2, the CPU 60 sends AF area information indicating the position,the size and the shape of the AF area (AF frame) to the CPU 50 of thelens unit 12. The position, the size and the shape of the AF area in theAF processing unit 52 of the lens unit 12 or in the viewfinder 36 is setbased on the AF area information. The CPU 60 changes the position, thesize and the shape of the AF area in the AF processing unit 52 or theviewfinder 36 as described later by changing the position, the size andthe shape of the AF area indicated by the AF area information, based onoperation of the abovementioned joy stick 62 or the AF frame size/shapeadjustment dial 64 and a selected position of the AF frame adjustmentselection switch 66.

As shown in FIG. 2, the abovementioned joy stick 62 is attached with aposition sensor 68, which detects operation to the joy stick 62. Forexample, signals (voltage values) indicating an angle the joy stick 62tilts up or down and an angle the joy stick 62 tilts to the left or tothe right in response to operation of tilting it up or down or to theleft or to the right with the reference of the standing position takenby the joy stick 62 when it is not operated is outputted from theposition sensor 68 and provided for the CPU 60.

The CPU 60 reads the operating direction of the joy stick 62 based onthe signals from the position sensor 68. Based on the operatingdirection, the CPU 60 moves the position of the AF area 92 (AF frame 94)in the AF processing unit 52 of the lens unit 12 or in the viewfinder 36up or down or to the left or to the right in the imaging range 90 asshown in FIG. 5.

When the joy stick 62 is tilted to the left as one faces to the joystick 62, the position of the AF area 92 (AF frame 94) moves to the leftas an arrow A shows by a certain amount in the imaging range 60 shown inFIG. 5. Similarly, when the joy stick 62 is tilted to the right, up ordown, the position of the AF area 92 moves in the operating direction,such as to the right as an arrow B shows, up as an arrow C shows or downas an arrow D shows, by a certain amount.

The CPU 60 continuously transfers the position of the AF area 92 bymoving the position of the AF area 92 in the same direction as theoperating direction by a certain amount for each time period when thejoy stick 62 is tilted in a certain direction. The AF area 92 may movein the higher speed according to the amount of operation (tilted angle)of the joy stick 62.

As shown in FIG. 2, the abovementioned AF frame size/shape adjustmentdial 64 is attached with a position sensor 70, which detects operationto the AF frame size/shape adjustment dial 64. For example, a signal ofa value corresponding to a turned position, to which the AF framesize/shape adjustment dial 64 is set by turning operation with thereference of the certain turned position is outputted from the positionsensor 70 and provided for the CPU 60.

The CPU 60 reads the turned position of the AF frame size/shapeadjustment dial 64 based on the signal from the position sensor 70. TheCPU 60 detects which of the two selectable positions shown in FIG. 4 theAF frame adjustment selection switch 66 is set to.

When the AF frame adjustment selection switch 66 is set to the positionfor selecting the size adjustment (adjustment of the size) (the lowerposition in FIG. 4), the CPU 60 makes the size of the AF area 92 (AFframe 94) bigger or smaller in the AF processing unit 52 in the lensunit 12 or on the viewfinder 36 as shown in FIG. 6 based on the turnedposition of the AF frame size/shape adjustment dial 64.

When a value indicating the turned position of the AF frame size/shapeadjustment dial 64 is operated in the direction where the value isbigger than the current value, the CPU 60 makes the AF frame 94 shown bya solid line corresponding to the current value shown in FIG. 6 biggerwhile keeping the center position and the aspect ratio of the AF area 92as they are, as the AF frame 94 shown by a dotted line. When a valueindicating the turned position of the AF frame size/shape adjustmentdial 64 is operated in the direction where the value is smaller than thecurrent value, the CPU 60 makes the AF frame 94 smaller while keepingthe center position and the aspect ratio as they are. The turnedpositions of the AF frame size/shape adjustment dial 64 are indicated bythe continuous values and the size of the AF frame 94 is continuouslytransferred according to increasing or decreasing of the value.

When the AF frame adjustment selection switch 66 is set to the positionfor selecting the shape adjustment (the upper position in FIG. 4), theCPU 60 changes the shape of the AF area 92 (AF frame 94) in the AFprocessing unit 52 of the lens unit 12 or in the viewfinder 36 as shownin FIG. 7 based on the turned position of the AF frame size/shapeadjustment dial 64.

When a value indicating the turned position of the AF frame size/shapeadjustment dial 64 is operated in the direction where the value isbigger than the current value, the CPU 60 changes the shape of the AFarea 92 so that the vertical width (width in the direction of Y) of theAF frame 94 shown by a solid line corresponding to the current valueshown in FIG. 7 is longer (so that the horizontal width is shorter) likethe AF frames 94 shown by dotted lines indicated by arrows A and B,while keeping the center position and the area of the AF area 92 as theyare. When a value indicating the turned position of the AF framesize/shape adjustment dial 64 is operated in the direction where thevalue is smaller than the current value, the CPU 60 changes the shape ofthe AF area 92 so that the horizontal width (width in the direction ofX) of the AF area 92 is longer (so that the vertical width is shorter)like the AF frame 94 shown by a dotted line indicated by an arrow C,while keeping the center position and the area of the AF area 92 as theyare. The shape of the AF frame 94 is also continuously transferredaccording to continuous increasing or decreasing of the value of the AFframe size/shape adjustment dial 64.

When the position sensor 70 detects the absolute position as detectionof a turned position of the AF frame size/shape adjustment dial 64, thesize or the shape of the AF area 92 is set according to the absoluteposition. By switching between the size adjustment and the shapeadjustment by the AF frame adjustment selection switch 66 in this case,the size or the shape of the AF area 92 changes according to the turnedposition of the AF frame size/shape adjustment dial 64. The AF area 92can be adjusted to a desired size and shape even in this case, however,when the size adjustment and the shape adjustment are switched by the AFframe adjustment switch 66, the CPU 60 can be adapted not to change thesize and the shape of the AF area 92. For example, the CPU 60 detectsdeviation of the turned position of the AF frame size/shape adjustmentdial 64 from a reference position, which is the position of the AF framesize/shape adjustment dial 64 turned when the size adjustment and theshape adjustment are switched, and changes the size or the shape of theAF area 92 by the deviation. Accordingly, neither the size nor the shapeof the AF area 92 changes unless the turned position of the AF framesize/shape adjustment dial 64 is changed after the size adjustment andthe shape adjustment are switched. The size or the shape of the AF framecan be changed by operating amount (deviation of the turned position) ofthe AF frame size/shape adjustment dial 64 after the switching.

With the process of the AF area operating unit 54, the AF area 92 (AFframe) can be adjusted to a desired position, size or shape. The AFprocessing unit 52 focuses on the object in the AF area 92 and a rangeof the AF area 92 is displayed on the viewfinder 36. As a single AFframe size/shape adjustment dial 64 is used as an operating member foradjusting both the size and the shape of the AF area 92, a space forplacing operating members relating to operation of the AF area can bereduced.

In the abovementioned embodiment, the case where the AF area operatingunit 54 is placed in the focus demand 26 has been described, however,the AF area operating unit 54 may be adapted by a controller dedicatedfor the purpose or placed in the zoom demand 28. The AF area operatingunit 54 may also be placed at a desired position such as in a lens unit12 or in a camera body 14.

When the lens unit 12 is a portable, so-called ENG lens, as shown inFIG. 8, the lens barrel 100 has operation rings 102, 104 and 106 foradjusting focus, zoom and iris. On the side of the lens barrel 100, adriving unit 108 for driving the operation rings 102, 104 and 106 bymotor is attached. On the case of the driving unit 108, variousoperating members including a zoon seesaw switch 110 for operating azoom and a VTR switch 112 are placed. The AF area operating unit 54 inthe abovementioned embodiment may be placed in the driving unit 108 andmay have the joy stick 62, the size/shape adjustment dial 64 and the AFframe adjustment selection switch 66 the same as those in FIG. 4 on thebackside of the case of the driving unit 108 as shown in FIG. 8.

In the abovementioned embodiment, the case where the joy stick 62 isused as a directional member for indicating the direction in which theAF area moves has been described, however, the directional member is notlimited to the joy stick. Any operating member may be applied to thedirectional member if only it can indicate a direction such as atrackball, a cross key, or four switch members arranged in placesindicating up, down, left and right.

In the abovementioned embodiment, both the size and the shape of the AFarea can be adjusted by a single operating member, however, theinvention can be adapted to adjust all of the position, the size and theshape of the AF area by a single operating member. For example, theinvention can be adapted to have the joy stick 62 shown in FIG. 4 and aselection switch for selecting a desired adjustment from the positionadjustment, the size adjustment, and the shape adjustment of the AF areaso that the joy stick 62 can be used for performing the adjustmentselected by the selection switch.

The present invention can be applied to an AF of the scheme other thanthe contrast scheme like the abovementioned embodiment.

Now, another embodiment of an auto-focus system according to the presentinvention will be described. FIG. 9 is a block diagram showing aconfiguration of an auto-focus system of an embodiment applied to thetelevision camera system shown in FIG. 1. The auto-focus system shown inFIG. 9 includes a lens unit 12, a camera body (camera head) 14, aviewfinder 36 and an AF area operating unit 54.

The lens unit 12 has a built-in CPU 220 and a built-in AF processingunit 222. The lens unit 12 also has an optical system (taking lens) (notshown) for forming an image of an object light on an imaging surface ofan imaging element of the camera body 14. The optical system has a groupof movable lenses, which is held in a lens barrel and can move to andfro along an optical axis, such as a focus lens for adjusting a focus ora zoom lens for adjusting a zoom, and a group of lenses fixed in thelens barrel. The group of movable lenses is driven by a motor (notshown) according to a control signal from the CPU 220. The CPU 220controls the position or the speed of the focus lens or the zoom lens.

The focus lens is controlled (focus control) by manual focus (MF) orauto focus (AF). When it is controlled by MF, a focus demand(controller) (not shown) connected with the lens unit 12 via a cable orthe like, for example, is used. The focus demand has a manual operatingmember (focus knob) for a cameraman to focus, and a focus control signaloutputted from the focus demand according to the operation are providedfor the CPU 220 of the lens unit 12. Then, the focus lens is controlledto move to the target position indicated by the focus control signal.

When it is controlled by AF, focus information (focus evaluation value)detected by an AF processing unit 222 is provided for the CPU 220 andthe focus lens is controlled according to the focus information. In thecamera body 14, an image signal of the image taken by the imagingelement is generated and the image signal (a brightness signal) isprovided from the camera body 14 to the AF processing unit 222. The AFprocessing unit 222 detects a contrast in the object image based on theimage signal.

Assuming that an object or a range of an object image, which iseffectively imaged by the imaging element of the camera body 14, iscalled “imaging range”, an AF area 252, which is an object range of AF,is set in a rectangular range of an AF frame 254 for the imaging range250, for example, as shown in FIG. 10. The position, the size (area) andthe shape (aspect ratio) of the AF area 252 (AF frame 254) in theimaging range 250 are changed according to AF area information providedfrom the AF area operating unit 54 as described later. The imaging range250 shown in FIG. 10 corresponds to an imaging range of a televisioncamera as well as to a screen range of an object image taken by theimaging element of the camera body 14 when the image is displayed on ascreen of the viewfinder 36 or the like.

In FIG. 9, image signals provided from the camera body 14 to the AFprocessing unit 222 include image information on the entire of theabovementioned imaging range. The AF processing unit 222 extracts onlythe image signals in the range of the AF area from the image signals andadds up high frequency components of the image signals for each field(for each screen). This sequentially gives values indicating contrastsof an object image in an AF area. The value (added up value) is called“focus evaluation value” in this specification.

The CPU 220 sequentially obtains the focus evaluation values as focusinformation from the AF processing unit 222 and moves the focus lens tothe position where the focus evaluation value is the biggest (maximum).This enables an object in the AF area is automatically focused on.

Image signals obtained by the imaging element of the camera body 14 areprovided from the camera body 14 for the viewfinder 36, whose screen isadapted to display the currently taken image. The CPU 220 of the lensunit 12 is adapted to provide AF area information (information on theposition, the size and the shape of the AF area) for the camera body 14,indicating a range of the abovementioned AF area, which is currently setas an object range of AF. Signals of the AF frame (an outline of the AFarea) indicating the range of the current AF area is combined with theabovementioned image signals to be outputted to the viewfinder 36, basedon the AF area information in the camera body 14, and an image of an AFframe 254 indicating a range of the current AF area 252 is displayed onthe screen of the viewfinder 36 with the image of the entire imagingrange 250, as shown in FIG. 10. With this display, the cameraman canrecognize the range of the current AF area.

The AF area operating unit 54 is an operating unit for setting andchanging the position, the size and the shape of an AF area, andconnected with the lens unit 12 via a cable or the like. The AF areaoperating unit 54 can be integrated in a unit for another purpose suchas a focus demand. FIG. 11 is a plane view showing an outline of an AFarea operating unit. As shown in FIG. 11, on the AF area operating unit54, a joy stick 232, an AF frame size adjustment dial 234 and an AFframe shape adjustment dial 236 are placed.

The joy stick 232 is a directional member for adjusting the position ofan AF area (AF frame). When the joy stick 232 is tilted up or down, orto the left or to the right, the position (center position) of the AFarea moves up or down or to the left or to the right on the screen (onthe imaging range) with the size and the shape of the AF area kept asthey are, as described later.

The AF frame size/shape adjustment dial 234 is an operating member foradjusting the size, i.e., the area of the AF area (AF frame). When theAF frame size adjustment dial is turned, the size (the area) of the AFarea is changed, while the center position and the shape of the AF areaare not changed as described later.

The AF frame shape adjustment dial 236 is an operating member foradjusting the shape of an AF area (AF frame), i.e., a ratio (aspectratio) of the vertical length (vertical width) and the horizontal length(horizontal width) of a rectangular AF area. When the AF frame shapeadjustment dial 236 is turned, the aspect ratio of the AF area ischanged, while the center position and the area of the AF area are notchanged as described later.

As shown in FIG. 9, the AF area operating unit 54 has a CPU 230 mountedon it. The CPU 230 sends AF area information indicating the position,the size (the area) and the shape (the aspect ratio) of the AF area tothe CPU 220 of the lens unit 12. The position, the size, and the shapeof the AF area in the AF processing unit 222 of the lens unit 12 or onthe viewfinder 36 are set according to the AF area information. The CPU230 changes the position, the size and the shape of the AF area in theAF processing unit 222 or on the viewfinder 36 as described below bychanging the position, the size and the shape of the AF area indicatedby the AF area information according to operation to the abovementionedjoy stick 232, AF frame size adjustment dial 234 and AF frame shapeadjustment dial 236.

The abovementioned joy stick 232 is attached with a position sensor 238,which detects operation to the joy stick 232. For example, signals(voltage values) indicating an angle the joy stick 232 tilts up or downand an angle the joy stick 232 tilts to the left or to the right inresponse to operation of tilting it up or down or to the left or to theright with the reference of the standing position taken by the joy stick232 when it is not operated is outputted from the position sensor 238and provided for the CPU 230.

The CPU 230 reads the operating direction of the joy stick 232 based onthe signals from the position sensor 238. Based on the operatingdirection, the CPU 230 moves the position of the AF area 252 (AF frame254) in the AF processing unit 222 of the lens unit 12 or on theviewfinder 36 up or down (in the direction of Y) or to the left or tothe right (in the direction of X) in the imaging range 250. When theposition of the AF area is changed, the size (area) and the shape(aspect ratio) of the AF area are kept to certain values.

When the joy stick 232 is tilted to the left as one faces to the joystick 232, the position of the AF area 252 (AF frame 254) moves to theleft as an arrow A shows by a certain amount in the imaging range 250shown in FIG. 12. Similarly, when the joy stick 232 is tilted to theright, up or down, the position of the AF area 252 moves in theoperating direction, such as to the right as an arrow B shows, up as anarrow C shows or down as an arrow D shows, by a certain amount.

The CPU 230 continuously transfers the position of the AF area 252 bymoving the position of the AF area 252 in the same direction as theoperating direction by a certain amount for each time period when thejoy stick 232 is tilted in a certain direction. The AF area 252 may bemoved in the higher speed according to the amount of operation (tiltedangle) of the joy stick 232.

As shown in FIG. 9, the abovementioned AF frame size adjustment dial 234is attached with a position sensor 240, which detects operation to theAF frame size adjustment dial 234. For example, a signal of a valuecorresponding to a turned position, to which the AF frame sizeadjustment dial 234 is set by turning operation with the reference ofthe predetermined turned position is outputted from the position sensor240 and provided for the CPU 230.

The CPU 230 reads the turned position of the AF frame size adjustmentdial 234 based on the signal from the position sensor 240. Then, the CPU230 makes the size, i.e., the area of the AF area in the AF processingunit 222 of the lens unit 12 or on the viewfinder 36 bigger or smallerbased on the turned position of the AF frame size adjustment dial 234.When the size of the AF area is changed, the position (center position)and the shape (aspect ratio) of the AF area are kept to certain values.

When a value indicating the turned position of the AF frame sizeadjustment dial 234 is operated in the direction where the value isbigger than the current value, the CPU 230 makes the area of the AF areabigger while keeping the center position and the aspect ratio of the AFarea as they are. In this manner, the AF frame 254 shown by a solid linecorresponding to the current value is expanded to the AF frame 254Ashown by a dotted line in the imaging range 250 shown in FIG. 13.

When a value indicating the turned position of the AF frame sizeadjustment dial 234 is operated in the direction where the value issmaller than the current value, the CPU 230 makes the area of the AFarea smaller while keeping the center position and the aspect ratio ofthe AF area as they are. In this manner, the AF frame 254 shown by asolid line corresponding to the current value is reduced to the AF frame254B shown by a dotted line in the imaging range 250 shown in FIG. 13.

The turned positions of the AF frame size adjustment dial 234 areindicated by continuous values and the size (the area) of the AF area iscontinuously transferred according to increasing or decreasing of thevalue. For the size (the area) of the AF area, however, a desired sizemay be selected from some determined sizes instead of the continuoustransfer.

As shown in FIG. 9, the abovementioned AF frame shape adjustment dial236 is attached with a position sensor 242, which detects operation tothe AF frame shape adjustment dial 236. For example, a signal of a valuecorresponding to a turned position, to which the AF frame shapeadjustment dial 236 is set by turning operation with the reference ofthe predetermined turned position is outputted from the position sensor242 and provided for the CPU 230.

The CPU 230 reads the turned position of the AF frame shape adjustmentdial 236 based on the signal from the position sensor 242. Then, basedon the turned position of the AF frame shape adjustment dial 236, theCPU 230 changes the shape of the AF area, i.e., the aspect ratioindicating a ratio of the vertical length and the horizontal length ofthe AF area in the AF processing unit 222 of the lens unit 12 or on theviewfinder 36. When the aspect ratio of the AF area is changed, thecenter position and the area (the size) of the AF area are kept tocertain values. An aspect ratio of an AF area means a ratio of thevertical (in the direction of Y) length (V) and the horizontal (X)length (H) of a rectangular AF area. In this specification, a value of(H/V) represents the size of the aspect ratio.

When a value indicating the turned position of the AF frame shapeadjustment dial 236 is operated in the direction where the value issmaller than the current value, the CPU 230 makes the aspect ratio ofthe AF area smaller by making the vertical length of the AF area longerand the horizontal length shorter to keep the area of the AF area to acertain value. In this manner, the AF frame 254 shown by a solid linecorresponding to the current value is changed to the AF frame 254A shownby a dotted line in the imaging range 250 shown in FIG. 14. When a valueindicating the turned position of the AF frame shape adjustment dial 236is further operated in the direction where the value is smaller, theaspect ratio is further smaller and the AF frame 254 is changed to theAF frame 254B shown by a dotted line in FIG. 14.

When a value indicating the turned position of the AF frame shapeadjustment dial 236 is operated in the direction where the value isbigger than the current value, the CPU 230 makes the aspect ratio of theAF area bigger by making the vertical length of the AF area shorter andthe horizontal length longer to keep the area of the AF area to acertain value. In this manner, the AF frame 254 shown by a solid linecorresponding to the current value is changed to the AF frame 254C shownby a dotted line in the imaging range 250 shown in FIG. 14.

FIG. 15 shows how the aspect ratio of the AF area 252 (AF frame 254)shown in FIG. 14 is transferred. When a value of the AF frame shapeadjustment dial 236 is operated in the direction where the value issmaller, the aspect ratio of the AF frame 254 shown by a solid linecorresponding to the current value of the AF frame shape adjustment dial236 become smaller as those of the AF frames 254A and 254B shown bydotted lines. When the value of the AF frame shape adjustment dial 236is operated in the direction where the value is bigger, the aspect ratioof the AF frame 254 become bigger as AF frame 254C shown by a dottedline.

The aspect ratio of the AF area is continuously transferred according tocontinuous increasing or decreasing of the value of the AF frame shapeadjustment dial 236. For the aspect ratio of the AF area, a desiredaspect ratio may be selected from some determined aspect ratios insteadof the continuous transfer.

When an aspect ratio of the AF area is changed by operation to the AFframe shape adjustment dial 236, while the center position of the AFarea is not changed as described above, a part of range of the AF areamay stick out from the imaging range. In such a case, the range of theAF area sticking out from the imaging range may be made invalid AF area(not considered as an object range of AF), or the position of the AFarea may be changed so that the entire AF area is contained in theimaging range.

The latter case will be described. When an edge of the AF area (AFframe) overlaps an edge of the frame of the imaging range and the aspectratio is changed, which causes the edge of the AF frame to expand fromthe imaging range, the changing of the aspect ratio is performed bymoving the position of the AF area so that the edge position of the AFframe is fixed. In this manner, the entire AF area can be contained inthe imaging range. According to this case, the right edge of the currentAF frame 254 shown by a solid line overlaps the right edge of theimaging range 250 as shown in FIG. 16, for example. When the aspectratio of the AF area is made bigger by the AF frame shape adjustmentdial 236 to change it to the AF area with the aspect ratio of the AFframe 254A shown by a dotted line in FIG. 16, the center position of theAF area moves from the center position 60 of the AF frame 254 to thecenter position 60A of the AF frame 254A so that the right edge positionof the AF frame 254A overlaps the right edge position of the imagingrange 250. When the aspect ratio of the AF area is further made biggerto change it to the AF area with the aspect ratio of the AF frame 254Bshown by a dotted line in FIG. 16, the center position of the AF areamoves from the center position 60A of the AF frame 254A to the centerposition 60B of the AF frame 254B so that the right edge position of theAF frame 254B overlaps the right edge position of the imaging range 250.In this manner, the position of an AF area is changed so that the entireAF area is always contained in an imaging range.

In the embodiment, the shape (aspect ratio) of the AF area is changed,while the area of the AF area is kept to a certain value by operation tothe AF frame shape adjustment dial 236, however, the area is notnecessarily kept to a certain value. For example, the aspect ratio ofthe AF area can be changed by changing either the vertical length or thehorizontal length of the AF area according to operation to the AF frameshape adjustment dial 236. Alternatively, with two adjustment dials forchanging the vertical length and the horizontal length of the AF arearespectively, the aspect ratio of the AF area can be changed by changinga length in a desired direction in the AF area. If the invention isadapted to change the vertical length and the horizontal length of theAF area separately, the size (the area) of the AF area can be adjustedaccording to adjustment of both lengths. In such a case, a device forchanging the size (the area) of the AF area such as the AF frame sizeadjustment dial 234 is not needed in particular.

In the abovementioned embodiment, the AF area is assumed as rectangular;however, the present invention can be applied where the AF area is notrectangular. For example, the present invention can be applied to an AFarea even in the shape other than a rectangle (such as a circle), wherethe aspect ratio of the AF area in the shape is considered to indicate aratio of the maximum vertical length and the maximum horizontal length.

The abovementioned embodiment is described by the example where a joystick 232 is used as a directional member for indicating the position ofthe AF area, however, the directional member is not limited to the joystick and may be applied to any operating member if only it can indicatea direction such as a trackball, a cross key, or four switch membersarranged in places indicating up, down, left and right. The operationalmember for indicating the size (area) or the shape (aspect ratio) of theAF area is not limited to a dial and may be applied to other operationalmembers with the other styles.

The present invention can be applied to AF of a scheme other than thecontrast scheme as in the abovementioned embodiment.

1. An auto-focus system comprising: an auto-focus device for controllinga focus of a taking lens by making an object in a range of an AF area inan imaging range of a camera an auto-focus object and automaticallyfocusing on the object in the range of the AF area; a size/shapeadjustment operating member used for changing both the size and theshape of the AF area; a selection device for selecting a subject fromthe size and the shape of the AF area by operating the size/shapeadjustment operating member; and an AF area changing device for changingthe subject selected by the selection device based on the operation tothe size/shape adjustment operating member.
 2. The auto-focus systemaccording to claim 1, wherein the size/shape adjustment operating membercan be set to continuous operating positions and the AF area changingdevice transfers the subject selected by the selection device in acontinuous state when an operating position of the size/shape adjustmentoperating member is continuously changed.
 3. The auto-focus systemaccording to claim 1, further comprising a position adjustment operatingmember for changing a position of the AF area, wherein the AF areachanging device changes a position of the AF area based on operation tothe position adjustment operating member.
 4. The auto-focus systemaccording to claim 2, further comprising a position adjustment operatingmember for changing a position of the AF area, wherein the AF areachanging device changes a position of the AF area based on operation tothe position adjustment operating member.
 5. The auto-focus systemaccording to claim 1, wherein the size/shape adjustment operating memberis provided on a controller with an operating member for operating afocus or a zoom of the camera or on a driving unit set on the side of alens barrel of a taking lens.
 6. The auto-focus system according toclaim 2, wherein the size/shape adjustment operating member is providedon a controller with an operating member for operating a focus or a zoomof the camera or on a driving unit set on the side of a lens barrel of ataking lens.
 7. The auto-focus system according to claim 3, wherein thesize/shape adjustment operating member is provided on a controller withan operating member for operating a focus or a zoom of the camera or ona driving unit set on the side of a lens barrel of a taking lens.
 8. Theauto-focus system according to claim 4, wherein the size/shapeadjustment operating member is provided on a controller with anoperating member for operating a focus or a zoom of the camera or on adriving unit set on the side of a lens barrel of a taking lens.
 9. Anauto-focus system comprising: an auto-focus device for controlling afocus of a taking lens by making an object in a range of an AF area inan imaging range of a camera an auto-focus object and automaticallyfocusing on the object in the range of the AF area; an aspect ratioinputting device for indicating and inputting an aspect ratio of the AFarea; and an aspect ratio changing device for changing an aspect ratioof the AF area to the aspect ratio inputted by the aspect ratiooperating device.
 10. The auto-focus system according to claim 9,wherein the aspect ratio changing device changes an aspect ratio of theAF area while keeping the area of the AF area to a certain value bychanging the vertical length and the horizontal length of the AF area.11. The auto-focus system according to claim 9, wherein the aspect ratiochanging device changes an aspect ratio of the AF area by changingeither the vertical length or the horizontal length of the AF area. 12.The auto-focus system according to claim 9, wherein the aspect ratioinputting device comprises: a first inputting device for indicating andinputting an aspect ratio of the AF area when only the vertical lengthis changed while the horizontal length of the AF area being kept to acertain value; and a second inputting device for indicating andinputting an aspect ratio of the AF area when only the horizontal lengthis changed while the vertical length of the AF area being kept to acertain value, and wherein the aspect ratio changing device changes thevertical length of the AF area to the aspect ratio indicated andinputted by the first inputting device and changes the horizontal lengthof the AF area to the aspect ratio indicated and inputted by the secondinputting device.
 13. The auto-focus system according to claim 1,wherein the aspect ratio changing device changes an aspect ratio of theAF area without changing the center position of the AF area.
 14. Theauto-focus system according to claim 2, wherein the aspect ratiochanging device changes an aspect ratio of the AF area without changingthe center position of the AF area.
 15. The auto-focus system accordingto claim 3, wherein the aspect ratio changing device changes an aspectratio of the AF area without changing the center position of the AFarea.
 16. The auto-focus system according to claim 5, wherein the aspectratio changing device changes an aspect ratio of the AF area withoutchanging the center position of the AF area.
 17. The auto-focus systemaccording to claim 9, wherein the aspect ratio changing device changesan aspect ratio of the AF area without changing the center position ofthe AF area, if an entire range of the AF area is contained in theimaging range of the camera, and changes an aspect ratio of the AF areaby changing the center position of the AF area so that the entire rangeof the AF area is contained in the imaging range of the camera, if theentire range of the AF area is not contained in the imaging range of thecamera.
 18. The auto-focus system according to claim 12, wherein theaspect ratio changing device changes an aspect ratio of the AF areawithout changing the center position of the AF area, if an entire rangeof the AF area is contained in the imaging range of the camera, andchanges an aspect ratio of the AF area by changing the center positionof the AF area so that the entire range of the AF area is contained inthe imaging range of the camera, if the entire range of the AF area isnot contained in the imaging range of the camera.
 19. The auto-focussystem according to claim 9, further comprising: a size inputting devicefor indicating and inputting the size of the AF area; and a sizechanging device for changing the size of the AF area to the sizeinputted by the size inputting device while keeping the aspect ratio ofthe AF area as it is.
 20. The auto-focus system according to claim 12,further comprising: a size inputting device for indicating and inputtingthe size of the AF area; and a size changing device for changing thesize of the AF area to the size inputted by the size inputting devicewhile keeping the aspect ratio of the AF area as it is.
 21. Theauto-focus system according to claim 9, further comprising: a positioninputting device for indicating and inputting a position of the AF area;and a position changing device for changing a position of the AF area tothe position inputted by the position inputting device.
 22. Theauto-focus system according to claim 12, further comprising: a positioninputting device for indicating and inputting a position of the AF area;and a position changing device for changing a position of the AF area tothe position inputted by the position inputting device.